1. Field of the Invention
The invention relates to a continuous casting mold.
2. Description of the Prior Art
Continuous casting molds are generally tapered to take account of the shrinkage undergone by a continuously cast strand as it cools. Ideally, the taper allows the strand to remain in contact with the mold as the strand moves therethrough while maintaining the friction between the strand and the mold at low levels. Contact between the strand and the mold is desirable because heat transfer from the strand to the mold occurs much more efficiently than when an air gap is present between the strand and the mold.
The taper depends not only on the material being cast but also on the casting conditions which usually change during the course of a casting operation. Thus, for best results, the taper should vary with the casting conditions. This is not possible with the tube molds used for the casting of smaller sections but can be accomplished with the plate molds employed for larger sections. The plate molds currently in use are normally rectangular and have two wide plates and two narrow plates which make up the walls of the mold. The narrow walls are clamped between the wide walls, and systems have been developed for changing the inclinations of the narrow walls during a casting operation. As the inclinations of the narrow walls are changed, a change of taper occurs widthwise of the mold. However, the inclinations of the wide walls cannot be changed because gaps would form between the wide walls and the narrow walls.
The European Patent Application No. 0 241 825 discloses a plate mold in which all of the walls can be moved without creating gaps. In this mold, an edge face of each mold wall abuts a major face of a neighboring mold wall. The mold is intended to permit changes in cross section and taper during a casting operation. To this end, at least one of the mold walls is shiftable at an acute angle to its major faces by one or more threaded spindles. Furthermore, in one embodiment of the mold, one of the mold walls is pivotable on an axis perpendicular to its major faces while another of the mold walls is pivotable on an axis parallel to its major faces. In an additional embodiment of the mold, each of the mold walls is pivotable on an axis parallel to the major faces thereof. One of the mold walls is also slidable in a guide which allows such mold wall to follow the change in inclination of a neighboring mold wall. As an alternative to the slidable mounting of a mold wall, the European Patent Application teaches that elastic buffers can be provided between the mold walls and their drive spindles in order to absorb small pivoting motions.
The mold of the European Patent Application is somewhat cumbersome and does not allow the taper to be changed as easily and effectively as desirable.